Fuel viscosity responsive control



Kl/VNATIC VISCOSITY (cs/vr/s TUKJ) Feb. 23, 1965 W. F. ISLEY ETAL FUEL. VISCOSITY RESPONSIVE CONTROL Filed April 25, 1962 FIGJ.

GASOLINE VISCOSI HIGHER TING (aw).

NORMAL NE AT 77F (ASSUMED H.H.V AS G ASOLIN vaL uMErx/c H51! rave VALUE 2 Sheets-Sheet. 1

NY .7l8 AT INVENTORS WALTER F. ISLEY FRANK C.DRUZYNSKI ATTORNEYS Feb:- 1955 w. F. ISLEY ETAL 3,17

FUEL VISCOSITY RESPONSIVE' CONTROL Filed April 23, 1962 2 Sheets-Sheet 2 as 7 US 24 o VISCOSITY RESPONSIVE as CONTROL DEVICE PUMP r ENGINE FUEL TANK'\- INVENTORS WALTER F. ISLEY By FRANK C.DRUZYN SKI ATTORNEYS 3,170,503 FUEL VISCOSITY RESPGNSIVE (IONTRQL Walter F. Isley, Grosse Pointe, and Frank' C. Druzynski, Bloomfield Township, Mich assignors to Continental Aviation and Engineering Corporation, Detroit, Mich,

a corporation of Virginia Filed Apr. 23, 1962, Ser. No. 189,378

15 Claims. (Cl. 158-36) This invention relates to multifuel engines and more particularly to a control system forautomatically varying the quantity of fuel for such an engine to maintain a maximum power output for any fuel being used.

Multifuel engines are calledupon to operate with .fuels having wide variations in heating value per gallon. When equipped with conventional type injection systems which meter essentially a constant volume for any fuel, the

. engine will produce a variation in maximum power proportional to theequivalent heating value of the volume of the fuel injected. a

An examination of the viscosity characteristics of fuels at varying temperatures shows a definite relationship between viscosity and fuel heating value. This viscosity characteristic is used as the sensed variable in the fuel control system of the present invention. In this way fuel is injected in quantities which will insure that maximum power output will remain constant with any fuel being used.

It is an object of the present invention to obtain a consistent maximum power output for'multifuel engines by providing a fuel control system which varies the volume of fuel in relation to its heating value per gallon.

It is another object of the present invention to provide a control for varying the flow of fuels to a multifuel engine which utilizes the proportional relationship between the viscosity, and the heatingvalue per gallon of the fuel being used 7 It is yet another object of the present invention to reduce manufacturing costs for fuel control systems for multifuel engines by providing a simply constructed, easily assembled and reliable control device, I Still further objects and advantages of the present invention will be apparent to one skilled in the art to which the invention pertains upon reference to the following drawing and description in which FIG. 1 is a chart showing the relationship between viscosity and heating value for several types of fuels and at different temperatures.L v FIG. 2 is a cross-sectional view of a preferred embod1- I merit of the present invention,

FIG. 3 is. a diagrammatic view illustrating the preferred relation of the/control to an engine.

' FIG. 1 illustrates the relationship between the viscosity and heating value of various fuels which is made use of v in the present invention. As can be seen on this chart, the

relationship is almost a single line for the various hydrocarbon fuels that are shown. By sensing changes in viscosity in effect it is possible to also sense changes in the heating value of the fuel being used. I

The fuel viscosity responsive device 100i the present invention as can best be seen in FIG. 2 preferably comprises a housing 11 provided with aninlet port 12 and a pair of parallel, bored portions 13 and 14. The housing 11 is capped at one end by a cap member 15 having a hollow, boss portion '16which extends into the bored 2. portion 13. The other end of the housing 11 is closed by an end member 17 having a recess 18 which aligns with the bored portion 13.

The inlet port 12 is adapted to be connected to a fuel the bore portion 14. The bore portion 14 aligns with a Unitfd tfi Patent recessed portion 19in the cap member 15 to provide'a control chamber 211. The bore 14 and the recessed portion 19 carry a piston 21 somewhat less in length than the chamber-20 and thus chambers 20A and 20B are formed at each end of the piston 21. The piston 21 is provided with a reduced portion .22 which provides variable communication between the inlet port 12 and a passage 23 open to the opposite side of the chamber 20. In operation, the piston 21 is urged into a position permitting full'fiow of fuel between the inlet port 12 and the passage 23 by a spring 24 seated in the recess 19. A passage 25 at all times openly connects the passage 23 to the chamber 203. An outlet port 26 connected to the fuel tank C, as seen in FIG. 3, communicates with the chamber 20A by means of an, outlet passage 27 provided in the cap member 15.

Fuel flows from the passage 23 into a peripheral chamber 28 formed by providing a reduced portion 29 .in the boss 16. The boss 16 is in effect a piston in the bore 13 and is sufficiently small to provide a peripheral orifice 30 between the boss 16 and bore 13, permitting fuel to flow from the chamber 28 to a pressure chamber 31 formed by the hollow portion 32 of the boss 16 and-an enlarged portion 33 provided in the bore portion 13.

A passage 34 directs the fuel from the pressure chamber 31 to the outlet passage 27 and thence to the fuel tank C. An adjustable needle valve 35 is provided to selectively restrict the flow of fuel from the passage 34 to the outlet passage 27. I i

A diaphragm 36 is disposed intermediate the, pressure chamber 31 and the aligned recess 18 provided in the end member 17. The diaphragm 36 is positioned by a spring 37 carried in the recess 18. The diaphragm 36 is 'operably connected to linkage 38 carrying a wedge shaped movable cam block 39. Injection pump control linkage 40 has an actuated element 40B frictionally engaging the block 39 and is-operably connected by suitable elements dtlC to the full load stop of the fuel pump A shown in FIG. 2. An escape passage 41 connects the recess portion 18 with the outlet passage 27.

In operation, fuel from the fuel pressure supply pump A is permitted to enter the inlet port 12. The. piston 21 acts to reduce the pressure of fuelin the chamber 28 to some constant value by balancing pressure-chamber 2 98 against fuel outlet pressure (substantially atmospheric) plus spring pressure. When the inlet pressure is greater than that desired, the excess pressure 'actsfth rough the passage 25 and the chamber 203 to lift the'piston 21 thereby tending to close communication between the inlet port 12 and the passage 23. It should be pointed out that various pressure regulating mechanisms may be sufficient for the purposes 7 of the invention and the invention is not intended to be limited to the valve structure illustrated. The valve need not even be a part of the housing but could be a separate structure fixed apart from the rest of the control mechanism. All that is necessary is that the fuel be reduced to .a constant pressure before entering the chamber 28 so that only changes in the'viscosity of the. fuel will be a determining factor and not changes in pressure produced by other variables.

The fuel then flows through the first orifice 3% formed by the boss portion 16 closely spaced from the bore 13. Fuel then flows to the second operative orifice which is the restriction formed by the needle valve 35 disposed between the passage 34 and the outlet passage 27. These two orifices have widely different flow characteristics and therefore have flow coefiicients which change with viscosity changes so that the pressure in the pressure chamber 31 will vary with the viscosity of the fuel. The position of the diaphragm 36 is therefore varied in accordance with this fuel pressure change produced by viscosity changes. The diaphragm 36' being connected j by suitable linkage 3.8 to the wedge shaped cam-block 39 which serves tovary the full load stop in the injection maintain constant. power output over a range of fuels is easily obtainediby a proper. selection of the wedge angle of the block 39. i a I Asis apparent fromthe chart shown in FIG. 1 fuel temperature affects fuel viscosity and without the inclusion of some compensating'feature for this effect the general tendency of the control illustrated would beto increase the amount of fuel injected beyond the desired .pump A. The amount of compensationgrequired'to" limits at-higher than normal ambient temperatures and decrease the amount injected below the desiredlimits 'at lower than normal'temp eratures. To compensate for these undesirable fuel temperature effects a combination material for the boss 16 and a relatively lower expansion material for the housing 11 would reduce the orifice 3t) with'increased temperature and enlarge it at lower temperature. A reduction in size of the orifice'tl would reduce the pressure in chamber 31 and thus fuel flow to the engine B would be reduced. A combination of materials can be selected which will produce an enlargement of the orifice at higher temperatures if this is desirable when the sensing device is used'for other purposes than controlling fuel injection. Thus the practical into said pressure chamber.

effect ofambient temperature changes on a properly selected combination of materials for the boss 16 and the housing ll'is to vary the degree of fuel quantity injected in desired proportions to matchengine requirements.

Inthe particular embodiment developed by us, the

housing '10 has been constructed of cast iron and the boss 16 of zinc. However, it is apparent that other material combinations could be used. g It isapparentthat if'the orifices and the orifice formed by the needle valve are reversed in flow order, a reversed effect will result. That is, the pressure in 31 will increase with an increase in the viscosity of the fuel being used. 1 V V -It is also apparent that although a preferred use of the viscosity sensingv device has been described as a means by which the fuel flow may be regulated in an internal combustion engine, other uses may also be made of the present invention. For instance, the device could be 'used as either a viscosity or-heating'value meter or sensor. Variousother changes andmodifications may be made without departing from ;the spirit of the in-- vention or the scope of'the appended claims.

. We claim:

1. In a multifuel enginehaving a fuel supply means, a a fuel control system comprising (a) means adaptedfor connection tosaid fuelsupply means and operable to regulate thefuel to apr'er' determined constant pressure, and (b) a viscosity responsive control device communicat= ing with said pressure regulating means and operable to vary the fuel delivered to' the engine by said fuel supply means, said device comprising a first orifice communicating 'with said pressure regulating means,

a second orifice connected in series; with said A being used, said pressure responsive means is operableto vary the amount ofuthe fuel de livered to the engine, and g temperature responsive means operable to vary the size of at least one of said orifices in response to temperature variations .in the fuel being delivered to rtheengine whereby "the amount of fuel being delivered to the engine will be 'varied'in response to viscosity changes inthe fuel being delivered.

2. The fuel controlsystem-as'defined'in vclaim 1 and .including means for manually adjusting the size of the other of said'orifices. r I

3.-The system defined in claim 2 and in which said pressure responsive means comprises a diaphragm memher and a spring memberurging' said diaphragm member 4. The fuel control system'asidefined' inclaim 1 and including (a) a first link mechanism'operably. connected at one a end to said pressure responsive'means,

' (b) a block having an inclined face and being secured to the other'end of said first link mechanism, and;

V (c) a second link mechanism fixed in relationship to said block and frictionally engaging said inclined face and adapted'for controlling connection with said fuel supply means whereby as said first link mech-.

' anism is moved in response to changes in pressure in said pressure chamber, a corresponding movement is produced in said second link mechanism.

5. In a multifuel engine having a fuelsupply means,

a fuel control system, and "pressure regulating -means adapted for connection withsaid fuel supply'rneans, a

viscosity responsive control device communicating with said pressure regulating means comprising, 7 (a) a housing having a. central hollow portion, '(b) a cap member'secured to oneend o'fsaid housing and having abossportion extending into said hollow,

portion, (c) said boss portion being sufiiciently smaller on its periphery than saidhollow portion tolprovide a pcripheral orifice between said boss portion and the periphery of said hollow portion,

'(d means conducting fuel from said pressurie regulating means to said peripheral orifice,

(e) an end member secured to the fend' ofisaid housing opposite said cap-member and having a recess open to andaxially aligned with said hollow portionof said housing, T Q 4 (1) said boss portion havinga recess facing said end member recessv to provide a'pressure chamber down stream of said'peripheral orifice, I

(g). pressure responsivemeans'disposedin said pressure chamber, 7v ,l (h) an outlet port being provided in said. cap member and communicating with saidpressure. chamber,

(i) adjustable restricting means disposed intermediate 7 said outlet and said pressure chamber to provide a manually adjustable orifice-therebetweem. and

6. The systemas defined in claim-5 and in-which said pressure regulating means'comprises a H (a) an inlet port adapted for connection with 'said fuel supply means, 1 Y

(b) an outlet communicating with s aid. firstforifice of said viscosity responsive cont-roldevice,

(c) a; controlchamber intermediate. said outlet and .said inlet, 1 a (d), a piston axially slidably carried in said. control (j) linking means operably connecting said pressure 7 responsive means; and said fuel supplvmeans wherechamber and operable to vary the communication between said inlet and said outlet,

() means urging said piston toward a fully opened position, and

(f) means operable to move said piston toward a closed position when the pressure of the fuel delivered to said inlet increases to a predetermined constant value.

7. The system defined in claim and in which said adjustable restricting means comprises an adjustable needle valve.

8. In a multifuel engine having a fuel supply means, and pressure regulating means adapted for connection with said fuel supply means, a viscosity responsive control device communicating with said pressure regulating means, and linking means operably connecting said viscosity control device and said fuel supply means,

(a) said viscosity responsive control device comprising a housing and means defining a first and second orifice disposed in said housing in series and having difierent fluid flow characteristics,

pressure responsive means connected intermediate said orifices and operable to sense pressure variations produced by changes in the viscosity of the fuel delivered to said device from said pressure regulating means, and

means operable to vary the size of at least one of said orifices in response to changes in the temperature of the fuel delivered from said pressure regulating means, and

(b) said linking means operably connecting said pressure responsive means and said fuel supply means to vary the fuel delivered to said engine in response to changes in the viscosity of the fuel as sensed by said pressure responsive means.

9. In a mult-ifuel engine having a fuel supply means, and pressure regulating means adapted for connection with said fuel supply means, a viscosity responsive control device communicating with said pressure regulating means, and linking means operably connecting said viscosity control device and said fuel supply means,

(a) said viscosity responsive control device comprising,

a housing having an inlet connected with said pressure regulating means and an outlet,

means defining an orifice in said housing intermediate said inlet and outlet and in communication with fuel flowing therethrough,

pressure sensing means disposed to sense pressure changes on one side of said orifice produced by variations in fuel viscosity,

means varying the size of said orifice in response to temperature changes of said fuel to compensate for viscosity variations produced by said temperature changes, and

(b) said linking means operably connecting said pressure sensing means and said fuel supply means to vary the fuel delivered to said engine in response to changes in the viscosity of the fuel as sensed by said pressure responsive means.

10. The system as defined in claim 9 and in which said orifice is a gap between two spaced elements, said elements having different coerlicients of thermal expansion.

11. The system as defined in claim 10 and in which said elements comprise radially spaced concentric cylinders.

12. The system as defined in claim 9 and in which said orifice is a gap defined by the outer periphery of one element and the inner periphery of a second element disposed concentric with the first element.

13. The system as defined in claim 8 and in which said temperature responsive means is operable to reduce the upstream orifice size with temperature increase to produce temperature compensation at said pressure responsive means.

14. The system as defined in claim 8 and in which said temperature responsive means is operable to increase the upstream orifice size with temperature increase to produce temperature compensation at said pressure responsive means.

15. The system as defined in claim 8 and in which said temperature responsive means is operable to increase the upstream orifice size and to decrease the downstream orifice size with temperature increases and decreases respectively to produce temperature compensation at said pressure responsive means.

References Cited in the file of this patent UNITED STATES PATENTS 1,534,091 Smoot Apr. 21, 1925 1,881,200 Leask et al. Oct. 4, 1932 1,899,396 Ray Feb. 28, 1933 2,579,215 Te Nuyl Dec. 18, 1951 2,859,768 Teague Nov. 11, 1958 2,917,067 Pearl Dec. 15, 1959 2,996,053 Evans Aug. 15, 1961 3,067,768 Burg Dec. 11, 1962 3,082,787 Elston et a1 -1 Mar. 26, 1963 FOREIGN PATENTS 272,061 Switzerland Feb. 16, 1951 868,228 Great Britain May 17, 1961 

1. IN A MULTIFUEL ENGINE HAVING A FUEL SUPPLY MEANS, A A FUEL CONTROL SYSTEM COMPRISING (A) MEANS ADAPTED FOR CONNECTION TO SAID FUEL SUPPLY MEANS AND OPERABLE TO REGULATE THE FUEL TO A PREDETERMINED CONSTANT PRESSURE, AND (B) A VISCOSITY RESPONSIVE CONTROL DEVICE COMMUNICATING WITH SAID PRESSURE REGULATING MEANS AND OPERABLE TO VARY THE FUEL DELIVERED TO THE ENGINE BY SAID FUEL SUPPLY MEANS, SAID DEVICE COMPRISING A FIRST ORIFICE COMMUNICATING WITH SAID PRESSURE REGULATING MEANS, A SECOND ORIFLCE CONNECTED IN SERIES WITH AND FIRST ORIFICE, A PRESSURE CHAMBER INTERMEDIATE SAID FIRST AND SAID SECOND ORIFICES, A PRESSSURE RESPONSIVE MEANS CARRIED IN SAID PRESSURE CHAMBER AND BEING ADAPTED FOR OPERABLE CONNECTION WITH SAID FUEL SUPPLY MEANS WHEREBY AS PRESSURE VARIES IN SAID PRESSURE CHAMBER IN RESPONSE TO CHANGES IN THE VISCOSITY OF THE FUEL BEING USED, SAID PRESSURE RESPONSIVE MEANS IS OPERABLE TO VARY THE AMONT OF THE FUEL DELIVERED TO THE ENGINE, AND TEMPERATURE RESPONSIVE MEANS OPERABLE TO VARY THE SIZE OF AT LEAST ONE OF SAID ORIFICES IN RESPONSE TO TEMPERATURE VARIATIONS IN THE FUEL BEING DELIVERED TO THE ENGINE WHEREBY THE AMOUNT OF FUEL BEING DELIVERED TO THE ENGINE WILL BE VARIED IN RESPONSE TO VISCOSITY CHANGES IN THE FUEL BEING DELIVERED. 